truck wont start

[eliotz28]

yes (well unless someone switched em before i got it)

[thunder550]

Hmmm ok. Well if you are sure that all of the grounds are hooked up and that there is no spark, next place to look would be the wiring to the coils. Let me get some screenshots up of the ignition schematics.

[thunder550]

I would start by checking power, ground, and signal wires to the coil packs. If you're not getting spark, one of these will not be working correctly.

[GasGuzzler]

An 04 Denali never came with a 5.3. Are you sure all your ducks are in a row? I'll look for another similar topic to link...

[GasGuzzler]

Have you read this topic?

http://www.ls1truck.com/forums/elect...schematic.html

[eliotz28]

Have you read this topic?

http://www.ls1truck.com/forums/elect...schematic.html

awesome thread so what im getting from it is his coils weren't grounded correctly besides his tps problems which as far as i know im not having

An 04 Denali never came with a 5.3. Are you sure all your ducks are in a row? I'll look for another similar topic to link...

thats what i was told when i bought it i do know its an 04 though because my 04 tac module seems to be working

[RedHeartbeat]

When you pulled the plugs did you touch the electrode to a clean metal part like a valve cover or something? The spark plug is normally grounded to the head through the threads, so when you pull it out you need to provide another ground for it.

The valve cover isn't a good ground, it floats completely on a bed of silicone, even the bolts holding it down have silicone or rubber isolators.

[eliotz28]

i tried grounding to the cylinder head ans no spark ill have to play with the ignition circuit tommorow

[thunder550]

The valve cover isn't a good ground, it floats completely on a bed of silicone, even the bolts holding it down have silicone or rubber isolators.

Oh, DUH! I should have known that

[GasGuzzler]

It just seemed like a similar problem.